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Related papers: Interpreting MAD within multiple accretion regimes

200 papers

Black hole (BH) X-ray binaries cycle through different spectral states of accretion over the course of months to years. Although fluctuations in the BH mass accretion rate are generally recognized as the most important component of state…

High Energy Astrophysical Phenomena · Physics 2024-03-28 M. T. P. Liska , N. Kaaz , K. Chatterjee , Razieh Emami , Gibwa Musoke

We present the results of nine simulations of radiatively-inefficient magnetically arrested disks (MADs) across different values of the black hole spin parameter $a_*$: $-0.9$, $-0.7$, $-0.5$, $-0.3$, 0, 0.3, 0.5, 0.7, and 0.9. Each…

High Energy Astrophysical Phenomena · Physics 2022-02-16 Ramesh Narayan , Andrew Chael , Koushik Chatterjee , Angelo Ricarte , Brandon Curd

The dynamics and structure of accretion disks, which accumulate the vertical magnetic field in the centers, are investigated using two- and three-dimensional MHD simulations. The central field can be built up to the equipartition level and…

Astrophysics · Physics 2009-11-13 Igor V. Igumenshchev

We use the public code ebhlight to carry out 3D radiative general relativistic magnetohydrodynamics (GRMHD) simulations of accretion onto the supermassive black hole in M87. The simulations self-consistently evolve a frequency-dependent…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Philippe Z. Yao , Jason Dexter , Alexander Y. Chen , Benjamin R. Ryan , George N. Wong

We perform three-dimensional radiation-relativistic magnetohydrodynamic (3D Rad-RMHD) simulations of accretion flows around spinning active galactic nuclei (AGNs). Our study focuses on the magnetically arrested disk (MAD) state, adopting a…

High Energy Astrophysical Phenomena · Physics 2026-03-13 Ramiz Aktar , Kuo-Chuan Pan , Toru Okuda

The remarkable results by the Event Horizon Telescope collaboration concerning the emission from M87* and, more recently, its polarization properties, require an increasingly accurate modeling of the plasma flows around the accreting black…

High Energy Astrophysical Phenomena · Physics 2021-07-23 Niccolò Tomei , Luca Del Zanna , Matteo Bugli , Niccolò Bucciantini

Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to…

Astrophysics · Physics 2011-02-11 Scott C. Noble , Julian H. Krolik , John F. Hawley

Radiative cooling can strongly influence the structure and dynamics of black hole accretion disks. Here, we perform general relativistic magnetohydrodynamic (GR-MHD) simulations of magnetically arrested disks (MADs) around a non-spinning…

High Energy Astrophysical Phenomena · Physics 2026-05-12 Akshay Singh , Damien Begue , Asaf Pe'er

We present axisymmetric numerical simulations of radiatively inefficient accretion flows onto black holes combining general relativity, magnetohydrodynamics, self-consistent electron thermodynamics, and frequency-dependent radiation…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Benjamin R. Ryan , Sean M. Ressler , Joshua C. Dolence , Alexander Tchekhovskoy , Charles F. Gammie , Eliot Quataert

There is a broad consensus that accretion onto supermassive black holes and consequent jet formation power the observed emission from active galactic nuclei (AGNs). However, there has been less agreement about how jets form in accretion…

High Energy Astrophysical Phenomena · Physics 2021-01-25 Shane W. Davis , Alexander Tchekhovskoy

Fast magnetic reconnection events can play an important role in accretion disk systems. A potential model to explain the non-thermal very-high-energy (VHE) emission (from GeV to TeV) observed in black-hole binaries (BHBs) and Active Galatic…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Luís H. S. Kadowaki , Elisabete M. de Gouveia Dal Pino , Tania E. Medina-Torrejón

We evolve two high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations of advection-dominated accretion flows around non-spinning black holes (BHs), each over a duration $\sim 3\times 10^5\,GM_{\rm BH}/c^3$. One model…

High Energy Astrophysical Phenomena · Physics 2022-12-21 Koushik Chatterjee , Ramesh Narayan

We present three-dimensional MHD simulations of rotating radiatively inefficient accretion flows onto black holes. In the simulations, we continuously inject magnetized matter into the computational domain near the outer boundary, and we…

Astrophysics · Physics 2009-11-07 Igor V. Igumenshchev , Ramesh Narayan , Marek A. Abramowicz

Context. The accretion of magnetized plasma onto black holes is a complex and dynamic process, where the magnetic field plays a crucial role. The amount of magnetic flux accumulated near the event horizon significantly impacts the accretion…

Recent results of the event horizon-scale images of M87* and Sagittarius A* from the Event Horizon Telescope Collaboration show that strong magnetic fields are likely present around the central black holes (BHs) in these sources.…

High Energy Astrophysical Phenomena · Physics 2025-09-19 Koushik Chatterjee , Matthew Liska , Alexander Tchekhovskoy , Sera Markoff , Ramesh Narayan

Recent advances in black hole astrophysics, particularly the first visual evidence of a supermassive black hole at the center of the galaxy M87 by the Event Horizon Telescope (EHT), and the detection of an orbiting "hot spot" nearby the…

Magnetically arrested accretion discs (MADs), where the magnetic pressure in the inner disc is dynamically important, provide an alternative mechanism for regulating accretion to what is commonly assumed in black hole systems. We show that…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Jason Dexter , Jonathan C. McKinney , Sera Markoff , Alexander Tchekhovskoy

Employing 3D GRMHD simulation, we study the images of a geometrically thin jet, whose emissions concentrate on its surface, for accretion system surrounding a central spinning BH. By introducing a strong magnetic field, we observe three…

High Energy Astrophysical Phenomena · Physics 2023-11-28 Ye Shen , Yehui Hou , Zhong-Ying Fan , Minyong Guo , Bin Chen

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Jonathan C. McKinney , Alexander Tchekhovskoy , Roger D. Blandford

We present a new approach for stably evolving general relativistic magnetohydrodynamic (GRMHD) simulations in regions where the magnetization $\sigma=b^2/\rho c^2$ becomes large. GRMHD codes typically struggle to evolve plasma above…

High Energy Astrophysical Phenomena · Physics 2024-07-16 Andrew Chael